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(11) | EP 0 435 438 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Input system including resistance film touch panel Eingabesystem mit berührungsempfindlicher Widerstandsfilmtafel Système d'entrée avec écran tactile à film résistif |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
[0001] This invention relates to an input system comprising a resistance film touch panel and a device for detecting a pushed position of the touch panel, especially the one including a device for conducting the above detection by use of a change in electric potential which occurs when the touch panel is pushed.
(2) Description of the Prior Art
[0002] A simple input system including a touch panel and a detecting device for detecting a pushed position of the touch panel and for outputting a signal which indicates the two-dimensional coordinates of the position is widely used in combination with a character display device (CRT, LCD or PDP) or the like.
[0003] In an input system including a resistance film touch panel, a pushed position of the touch panel, namely, the position where two resistance films are contacted on each other, is detected based on the resistance value of the position -- contrary to using capacitance.
[0004] Conventionally, two types of touch panels comprising resistance films have been offered: analog system touch panels and matrix system touch panels.
[0005] Fig. 1 shows an analog system touch panel. Two resistance films 91 and 92 are opposed to each other with a certain distance therebetween. The film 91 has outer connecting electrodes 93 and 94 along ends thereof, the ends extending along a Y axis; and the film 92 has outer connecting electrodes 95 and 96 along ends thereof, the ends extending along an X axis. In this construction, a pushed position A or B is detected by obtaining a resistance value r1 or r3 between the position A or B and the outer connecting electrode 95 and a resistance value r2 or r4 between the position A or B and the outer connecting electrode 93 and then converting the obtained resistance values into a voltage, which is outputted through the electrodes 94 or 96.
[0006] If the two points A and B are pushed simultaneously, r1 and r3 are connected in parallel and r2 and r4 are connected in parallel, thereby combined resistances are formed. The voltage is divided by the combined resistances, resulting in finding a position which is neither A nor B. Therefore, accurate detection of two pushed positions are impossible with this construction.
[0007] As shown in Fig. 2, a matrix system touch panel comprises a plurality of strip-like resistance films 101 arranged in parallel and a plurality of strip-like resistance films 102 arranged in parallel. The films 101 are extended along the X axis and the films 102 are extended along the Y axis, the films 101 and the films 102 having a certain distance therebetween. A pushed position is detected by finding out which films are contacted on each other by use of an appropriate scanner.
[0008] Since each film has a lead connected thereto, a great number of leads are necessary, which causes the wiring area to be too large compared with the detection area of the touch panel. Also required are a large number of input circuit components. These facts increase size of the system and manufacturing cost.
[0009] In an effort to minimize the number of the leads, touch panels are manufactured these days with various numbers of films for different usages. However, the necessity of manufacturing products with various numbers of films brings about another troublesome matter such as management of various components.
[0010] JP-A-59 127 181 discloses a resistive touch panel comprising a conductive film divided into parts on one side of a pressure-sensitive sheet together with a resistance film provided on the other side of the sheet. A voltage is supplied to the parts of the conductive film one by one via switches. When pressure is applied to a point on the touch panel, one of the parts of the conductive film makes contact with the underlying resistive film. Both coordinates of this point are determined by measuring the voltage dropped across external resistors connected to the underlying resistive film. The preamble of each of the claims 1 and 12 is based on JP-A-59 127 181.
SUMMARY OF THE INVENTION
[0011] Accordingly, this invention has an object of offer an input system including a resistance film touch panel and a pushed position detecting device for accurately detecting two or more positions pushed simultaneously with a minimized number of leads.
[0012] According to a first aspect of the invention the above object is fulfilled by an input system as defined by claim 1. According to a second aspect of the invention there is provided a resistance film touch panel as defined by claim 12. Preferred features of the invention are defined in the dependent claims.
[0013] In the present invention, since the first resistance film extends in first and second directions, the touch panel requires approximately only half the electrodes compared with the matrix system touch panel as well as a smaller wiring area and fewer input circuit components. Thus a simple construction is obtained with lower manufacturing cost.
[0014] If two or more positions are pushed simultaneously at least in the first or the second direction, the strip-like second resistance films can be selected one by one to allow each of the positions to be accurately detected.
[0015] Also according to preferred feature, the potentials at both ends of each strip-like resistance film are detected alternately. Even an area defined by two or more points is pushed, the outer periphery thereof can be detected with a small number of leads.
[0016] Further, when the touch panel comprises a resistance film extended two-dimensionally and formed on the upper base layer on which an external force is to be applied and a plurality of strip-like resistance films formed on the lower base layer, the touch panel is easy to manufacture and moreover, enhance yield rate for the following reason.
[0017] The upper base layer should be thin because it is to be pushed by a finger or the like. Much care should be taken in forming the resistance film on such a thin upper base layer. Since no laser trimming or other processing is necessary in forming the resistance film extended two-dimensionally in contrast to the strip-like ones, there is no worry of spoiling the upper base layer.
[0018] On the other hand, used for the lower base layer is a hard and thick plate which is tough enough to withstand laser trimming for forming the strip-like resistance films.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention. In the drawings:
Figs. 1 and 2 are views showing conventional touch panels;
Fig. 3 is a plan view of a touch panel of an embodiment according to this invention;
Fig. 4 is a cross sectional view along the A-A line of Fig. 3;
Figs. 5a and 5b show examples of the construction of a resistance film;
Fig. 6 shows an overall construction of the embodiment;
Figs. 7a, 7b and 7c show the principle of detecting the pushed position;
Figs. 8, 9 and 10 show other embodiments of this invention;
Fig. 11 is an exploded perspective view of still another embodiment of this invention;
Fig. 12 is a view of the embodiment of Fig. 11 combined with a character display device;
Fig. 13 is a bottom view of an upper plate of the embodiment of Fig. 11;
Fig. 14 is a top view of a lower plate of the embodiment of Fig. 11;
Fig. 15 is a view showing a printed circuit board of the system of Fig. 11;
Fig. 16 is an enlarged view of the part A of Fig. 15;
Fig. 17 is a view of still another embodiment of this invention; and
Figs. 18, 19 and 20 are views of modifications of Fig. 17.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] A first embodiment according to this invention will be described with reference to Fig. 3 through 8.
[0021] As shown in Figs. 3 and 4, a touch panel of the system comprises two insulating base layers 1 and 2, a resistance film 3, a plurality of resistance films 4 (eight in this embodiment), and spacers 5 for keeping a certain distance between the resistance films 3 and 4. The films 3 and 4 are respectively formed on main surfaces 1a and 2a of the base layers 1 and 2.
[0022] The insulating base layers 1 and 2 are formed of transparent polyethylene terephthalete films in this embodiment. Also employable are glass, plastics and other insulating materials which have an appropriate flexibility or elasticity.
[0023] The resistance film 3 is extended along the X and y axes crossing each other perpendicularly. The resistance film 3 desirably has a uniform surface resistance value (will be referred simply to resistance value, hereinafter) for accurate detection with the maximum tolerance of ±2%. Such a film is produced by sputtering, ion-plating or coating an oxide of indium and tin, other metals or metal oxides. The resistance film 3 has outer connecting electrodes (for example, formed of silver) at both ends thereof, the ends extending along the Y axis.
[0024] The resistance films 4 are lengthy strips arranged in parallel, each film being extended along the X axis. The resistance value of the film 4 is not required to be uniform but is favorably ten to a hundred times higher than that of the film 3 so that the resistance value of each film 4 may not affect the electric potential slope of the film 3 even if the film 4 is contacted on the film 3.
[0025] The resistance films 4 are formed, for example, by sputtering an oxide of indium and tin on the surface 2a before etching. Forming the films 4 of the same material as the film 3 as in this embodiment generates no problem since each film 4 has a bigger resistance value due to its smaller surface area compared with the film 3. The resistance value of each film 4 is further increased by making cutoffs 9 from both longer sides thereof alternately (Fig. 5b). With the cutoffs 9, the electric current path is half as wide and twice as long as the current path without the cutoffs (Fig. 5a). Therefore, the resistance value of the film 4 of Fig. 5b is four times higher than that of the film 4 of Fig. 5a. The resistance value can easily become a hundred times or more higher by making much more cutoffs. This type of resistance film is formed by screen printing or etching when only a small number of cutoffs are required, and by photolithography or laser processing when a large number of cutoffs are required.
[0026] Each film 4 has outer connecting electrodes 10 and 11 (formed of silver) at both ends thereof.
[0027] The films 4 may be provided in approximately the same number as the lines or rows of the conventional matrix system touch panel.
[0028] The spacers 5 are transparent cylinders formed of an insulating material and are provided in an appropriate number at appropriate positions so that they may not prevent the films 3 and 4 from contacting each other when the base film 2 is pushed. The spacers 5 may be non-transparent if the spacers 5 are small, and also may be small dots, globes, or semi-spheres.
[0030] In Fig. 6, analog switches 41 and 42 have the same construction and are controlled to connect their respective terminals 1 through 17 to terminals 18 one by one, in synchronization concerning the same-numbered terminals, by the controller 44 through a decoder 45. The terminals which are not connected to the terminal 18 are kept at high impedance.
[0031] In the analog switch 41, the terminal 18 is supplied with a DC potential V2 by an external power source, and the terminals 2 through 17 are to be connected with all the outer connecting electrodes 10 and 11, respectively. In this construction, V2 is supplied to all the electrodes 10 and 11 one by one.
[0032] In the analog switch 42, the terminal 1 is supplied with a DC potential V1, and the terminals 2 through 17 are to be connected with all the electrodes 10 and 11, respectively. The terminal 18 is connected to an A/D converter 43. In this construction, the potential which is supplied to the film 3 through the terminal 1 is outputted as the reference potential, thereafter the electric potentials of all the electrodes 10 and 11 are outputted one by one.
[0033] The terminals 2 through 17 of both analog switches 41 and 42 and the electrodes 10 and 11 have such a relationship that, while the electric potentials of the electrodes 10 and 11 are selectively outputted one by one, the analog switch 41 may apply V2 to the electrode belonging to the same film 4 as the selected one does.
[0034] For measuring the resistance value, the electrode 6 of the film 3 is supplied with V1, and the electrode 7 is grounded. The level of V2 is desirably the same or higher than that of V1.
[0036] The terminals 1 of the analog switches 41 and 42 are selected by the command from the decoder 45. The terminals 1 and 18 of the analog switch 41 have low impedances (ON), but the terminal 1 is connected to nothing. Therefore, power is supplied to none of the films 4. On the other hand, the terminals 1 and 18 of the analog switch 42 are connected to each other. Accordingly, V1 is A/D-converted by the A/D converter 43 and sent to the controller 44. The controller 44 stores the value of V1 for easy detection of the X coordinate of the pushed position.
[0037] Then, the terminals 2 of the analog switches 41 and 42 are selected, thereby the electrode 10 of the uppermost film 4 gets V2 through the terminal 18 of the analog switch 41. At this time, the potential of the electrode 11 of the same film 4 is conveyed to the terminals 2 and then 18, both of the analog switch 42, and to the controller 44 through the A/D converter 43.
[0038] If this potential is the same or higher than V1 supplied to the film 3, the uppermost film 4 is not pushed. In this case, the terminals 4 of the analog switches 41 and 42 are selected, thereby the second uppermost film 4 is pushed or not is detected in the same manner.
[0039] If the potential of the electrode 11 of the uppermost film 4 is smaller than V1, the uppermost film 4 is pushed. In this way, the Y coordinate of the pushed position is detected.
[0041] Figs. 7a, 7b and 7c show the relationship between the pushed position along the X axis and the potentials of the electrodes 6, 7, 10 and 11. The solid line indicates the potential slope of the film 3. Concerning each film 4, the electrode 10 is supplied with V2 and the electrode 11 has its potential measured through the analog switch 42. When the film 4 is not pushed, no power is supplied and therefore the potential of the electrode 11 is the same as V2 of the electrode 10 as shown with the chained line (Fig. 7a). As mentioned before, the resistance value of the film 4 is too high to have any affect on the potential slope of the film 3. Accordingly, when the film 4 is pushed and contacted on the film 3 at a point C, the potential of the point C of the film 4 is lowered down to VS, which is the same as that of the corresponding point of the film 3 (the dashed line of Fig. 7a). Then, the electrode 11 gets the same potential VS. The controller 44 obtains the X coordinate of the point C by use of the difference between VS and V1.
[0043] In Fig. 7b, points D and E indicate the left end and the right end of the pushed area, respectively. As apparent from Fig. 7b, the electrode 11 gets VR, namely, the potential of the point E, based on which the X coordinate of the point E is detected.
[0044] After the potential of the electrode 11 is outputted, the decoder 45 commands the analog switches 41 and 42 to select the terminals 3. By this selection, the electrode 11 is supplied with V2. On the other hand, the electrode 10 gets VL, namely, the potential of point D (Fig. 7c), based on which the X coordinate of the point D is detected. In this way, the X coordinates of the two points are detected.
[0045] The potentials of the electrodes 10 and 11 of the other films 4 are obtained one by one in the same way, whereby the X and Y coordinates of all the points that define the pushed area are detected.
[0046] In Fig. 6, a DC power source is connected to the terminal 18 of the analog switch 41 in order to supply a certain level of potential to the film 4 even when the film 4 is not pushed and thus to make the unpushed film distinct from the pushed film. The analog switch 41 and the DC power source may be eliminated so as to release the unpushed film from any potential although a little unstable electrically. In that case, the electrodes 10 and 11 of the pushed film 4 have VL and VR as shown in Fig. 8. In this construction, the potentials of all the electrodes 10 and 11 are selectively obtained by the analog switch 42 to detect the X coordinates of the points D and E.
[0047] Fig. 9 shows a second embodiment according to this invention. This embodiment is distinct from the first embodiment except the followings. All the films 4 share by a common electrode 71 at one ends thereof, the electrode 71 being supplied with the same potential as the electrode 6. The potentials of the electrodes 11 are selectively obtained by an analog switch 72. The number of the terminals of the analog switch 72 is larger by one than the number of the films 4.
[0048] In this construction, if the film 4 is pushed at two or more points, only the rightmost point is detected along the X axis. Along the Y axis, however, all the coordinates can be detected by obtaining the potential of each film 4.
[0049] Fig. 10 shows a third embodiment according to this invention. The electrodes 10 are all to be connected to an analog switch 81 and the electrodes 11 are all to be connected to an analog switch 82. The analog switches 81 and 82 are controlled to supply V1 to all the films 4 one by one, in synchronization concerning each film. The electrodes 6 and 7 of the film 3 are supplied with V2 through a switch 83, which is switched twice as fast as the analog switches 81 and 82. The electrodes 6 and 7 are also connected to the A/D converter through an analog switch 84, which is switched as fast as but reversely to the switch 83. The output from the A/D converter is sent to a controller (not shown). The switches 81 through 84 are switched by the controller through a decoder (not shown).
[0050] In this construction, when the analog switches 81 and 82 select one of the films 4, the selected film 4 gets the potential slope based on V1. At this time, the potentials of the electrodes 6 and 7 are obtained through the analog switch 84. This operation is repeated for all the films 4.
[0051] In this way, even if the film 4 is pushed at two or more points along the X axis, all the points can be detected. In this embodiment, each film 4 should have a uniform resistance value, which should be ten or a hundred times lower than that of the film 3.
[0053] This embodiment includes a touch panel comprising an insulating upper plate 201 to be pushed, an insulating lower plate 202, a transparent resistance film 203 formed on a lower surface 201a of the plate 201, a plurality of transparent resistance films 204 formed on an upper surface 202a of the plate 202, a cylindrical spacer 205 for keeping a certain distance between the resistance films 203 and 204, and a printed circuit board 214. The system is combined with a character display 208 (CRT, LCD, PDP or EL) as shown in Fig. 12 . The spacer 205 is formed of an insulating material and may be small dots, globes or semi-spheres.
[0054] The upper plate 201 is formed of a polyethylene terephthalete film in this embodiment, but plastics or other insulating materials which have an appropriate flexibility or elasticity can also be used. The upper plate 201 has a projecting portion 201b for forming leading electrodes. The lower plate 202 is formed of, for example, transparent glass which is excellent in resistance against chemicals. Also acceptable are polycarbonate and hard plastics which have excellent resistance against chemicals and laser.
[0055] As shown in Fig. 13, the resistance film 203 is extended along the X and Y axes, which cross each other perpendicularly. The film 203 is produced in the same way as the film 3 of the first embodiment. The film 203 has outer connecting electrodes 206 and 207 (for example, formed of silver) along both ends thereof, the ends extending along the Y axis. The projecting portion 201b has leading electrodes 215 through 218. The leading electrodes 215 and 216 are both connected to the outer connecting electrode 206, respectively through a power supply line 219 and a voltage sensing line 221. The leading electrodes 217 and 218 are both connected to the outer connecting electrode 207, respectively through a voltage sensing line 222 and a power supply line 220. The power supply lines 219 and 220 have larger cross sections than the voltage sensing lines 221 and 222 in order to keep voltage drop small.
[0056] As shown in Fig. 14, the resistance films 204 are lengthy strips arranged in parallel, the films 204 extending along the X axis. The resistance films 204 are produced by sputtering an oxide of indium and tin on the surface 202a and then masking it with screen printing or photolithography before etching it. Laser processing can be used instead of etching.
[0057] Forming the films 204 of the same material as the film 203 as in this embodiment generates no problem since each film 204 has a bigger resistance value due to its smaller surface area compared with the film 203. The resistance value of each film 4 is further increased by employing the construction illustrated in Fig. 5b.
[0058] Each film 204 has outer connecting electrodes 210 and 211 (formed of carbon-coated silver) at both ends thereof, which are connected to leading electrodes 230 formed on the lower plate 202 through connecting lines 231.
[0059] As shown in Fig. 15, the printed circuit board 214 is fixed on the upper surface 202a of the lower plate 202 and has a chip component 221 such as an IC mounted thereon. The printed circuit board 214 further has a connecter 222 fixed at an outer end thereof. Formed at an inner end of the printed circuit board 214 are electrodes 223 to be connected to the electrodes 230 and electrodes 225 to be connected to the electrodes 215 through 218. Each electrode 225 is formed of anisotropic conductive film. Each electrode 223 has a cutout 223a, with which a solder 224 for soldering the electrodes 223 and 230 is securely fixed (Fig. 16).
[0061] The electrodes 210 of the resistance films 204 are supplied with a common potential +V through serial resistances 276 and a common electrode 271. The serial resistances 276 are provided to regulate the amount of current flown into the resistance film 203 from the film 204 when the film 203 is pushed. If a DC voltage is directly supplied to the film 204 without the serial resistances 276, too much current is flown into the film 203, thereby to alter the potential slope between the pushed position and the electrode 207. This has an adverse influence on the accuracy of the pushed position detection. The electrode 206 of the film 203 is supplied with the potential +V through an external resistance 273, and the electrode 207 is grounded through another external resistance 274.
[0062] The potentials +V of the electrodes 206 and 207 of the film 203 are respectively led to reference inputs VREF(+) and VREF(-) of an A/D converter 272 through buffers 275. The potentials of the electrodes 211 of the film 204 are detected by the A/D converter 272 with a built-in analog switch. The A/D converter 272 has the same number of terminals with the number of the films 204.
[0063] In the above construction, if two or more positions of the same film 204 are contacted on the film 203, only the rightmost position is detected. Along the Y axis, however, all the pushed positions are detected by obtaining the potentials of all the films 204.
[0064] Fig. 18 shows a modification of the above construction. Here, serial circuits each consisting of a resistance 310 and a diode 311 is provided instead of the common electrode 271. The serial circuits are respectively connected to the electrodes 211 at one ends thereof and are grounded through a switch 312 at the other ends thereof. Although the switch 312 has a contact in Fig. 18, a non-contact type switch such as a transistor can be used as long as it is turned on periodically with an appropriate timing. If a certain film 204 is not contacted on the film 203 when the switch 312 is turned on, the electrode 211 of the film 204 gets the ground-level potential by the resistance 310 and the diode 311. If the film 204 is contacted on the film 203 when the switch 312 is turned on, the potential of the electrode 211 is changed to the potential of the film 203. Accordingly, whether the films 203 and 204 are contacted on each other or not is judged in the following way: if the input VIN of the A/D converter 272 is lower than the reference input VREF(-) (now shown) when the switch 312 is turned on, the touch panel is not pushed; if the input VIN is higher than the reference input VREF(-) when the switch 312 is turned on, the touch panel is pushed. In the latter case, the switch 312 is then turned off and the pushed position is detected. It is desirable that protecting diodes 313 and 314 are provided respectively between the +V and the electrode 211 and between the electrode 211 and the ground. The protecting diodes 313 and 314 prevent the input voltage of the A/D converter 272 from being broken by the induced voltage when switch 312 is off with the touch panel not being pushed.
[0065] Fig. 19 shows another modification of Fig. 17. In the construction of Fig. 17, the A/D converter 272 has the same number of terminals as the number of the film 204. However, an A/D converter usually has 8 input terminals. This means two or more expensive A/D converters are required if the number of terminals are increased to 16, 24, or even 32. The sixth embodiment is proposed to solve this problem of high cost. Used as the A/D converter is a single-chip microcomputer with a built-in A/D converter (will be referred simply to A/D converter, hereinafter), and a multiplexer is provided at the input side of each A/D converter. The plurality of the films 204 are connected to the A/D converter one by one by the multiplexer.
[0066] Practically, this embodiment has the following construction. Four commercially available ICs 321 through 324 (74HC4052 manufactured by NEC Corporation), each having two 4-input, 1-output multiplexers, are used. The outputs from the ICs 321 through 324 are supplied to an A/D converter 325 having 8 input terminals. Which output should be supplied to the A/D converter 325 is controlled moment by moment by a channel control signal supplied from the A/D converter 325.
[0067] Since this construction has 32 inputs in all, it can be applied to a touch panel having up to 32 strip-like films.
[0068] Fig. 20 shows still another embodiment in which 8 commercially available ICs 331 through 338 (74HC4051 manufactured by NEC Corporation), each of which has an 8-input, 1-output multiplexer, are used. An A/D converter 329 has 8 input terminals. Which output should be supplied to the A/D converter is controlled by the channel control signal. This construction can be applied to a touch panel having up to 64 strip-like films.
[0069] In all the above embodiments, the lengthy strip-like films cross the two-dimensional film perpendicularly. However, they may be deflected if a little. Theoretically, it is acceptable if only the strip-like films cross the Y axis.
[0070] Although the present invention has been fully described by way of embodiments with references to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
a spacer (5);
a continuous first resistance film (3, 203) extended in first and second directions, the first and second directions crossing each other perpendicularly and said first resistance film (3, 203) having an outer connecting electrode (6, 7, 206, 207) on both ends thereof along the second direction;
a plurality of second resistance films (4, 204), said second resistance films (4, 204) each being a lengthy strip extended in a direction crossing the second direction and having an outer connecting electrode (10, 71, 11, 210, 211) on at least one end thereof;
wherein said pushed position detecting device is adapted to detect one of said coordinates based on the surface resistance value of said first resistance film between one of the outer connecting electrodes of the first resistance film and the pushed position, characterised in that
a pair of insulating base layers (1, 201, 2, 202) is provided opposed to each other with a certain distance therebetween;
said spacer is provided between said insulating base layers (1, 201, 2, 202) for keeping said layers apart but for allowing said layers (1, 201, 2, 202) to approach each other when an external force is applied to one of the layers (1, 201, 2, 202);
said first resistance film is provided on an inner surface (1a, 201a) of one of said layers (1, 201); said plurality of resistance films is provided on an inner surface (2a, 202a) of the other of said layers (2, 202); and
said pushed position detecting device is further adapted to detect the other one of said coordinates based on the location of the second resistance films in said panel.
DC potential supplying means for supplying said first resistance film (203) with a DC potential (V) through one of the outer connecting electrodes (207) thereof;
a switch (312) switched to a first state for supplying all the outer connecting electrodes (211) of said second resistance films (204) with a ground-level potential and to a second state for releasing the same (211) from the ground-level potential; and
electric potential measuring means (272) for measuring the potentials of all the outer connecting electrodes (211) of said second resistance films (204) both in the first and the second states.
a first potential supplying means for supplying said first resistance film (3) with a DC potential (V1) through one of the outer connecting electrodes (6) of said first resistance film (3);
a first switch (41) electrically connected with all the outer connecting electrodes (10) of said second resistance films (4) one by one, alternately for said each second resistance film;
a second switch (42) switched in synchronization with the first switch (41) and electrically connected to the outer connecting electrode (11) which is opposed to the outer connecting electrode (10) connected to the first switch (41);
second potential supplying means for supplying said second resistance films (4) with a DC potential (V2) through the first switch (41); and
electric potential measuring means (43) for measuring potentials of the second resistance films (4) through the second switch (42).
DC potential supplying means (81, 82) for supplying a DC potential to said second resistance films (4) one by one;
switching means (83) switching at a speed at least twice as high as the DC potential supplying means (81, 82), said switching means (83) being for supplying a DC potential to the outer connecting electrodes (6, 7) of said first resistance film (3) alternately; and
electric potential measuring means (84) for measuring the potential of the outer connecting electrode (6 , 7) of said first resistance film (3), the electrode (6, 7) being opposed to the electrode (6, 7) supplied with the DC potential by the switching means (83).
a first potential supplying means for supplying said first resistance film (3) with a DC potential (V) through one of the outer connecting electrodes (6) of said first resistance film (3);
a second potential supplying means for supplying a DC potential (V) to the second outer connecting electrode (71) of said second resistance films (4);
a switch (72) electrically connected with the first outer connecting electrodes (11) of said second resistance films (4) one by one, alternately for said each second resistance film (4); and
electric potential measuring means (43) for measuring potentials of the first outer connecting electrodes (11) of the second resistance films (4) through the switch (72).
a continuous first resistance film ( 203) extending two-dimensionally;
a plurality of lengthy strip-like second films (204); and
a spacer (205) for keeping said first (203) and second (204) films apart but, when an external force is applied on said first (203) film allows the first (203) and the second (204) films to contact each other at a position corresponding to where the external force is applied;
characterised in that the first film (203) is formed on a lower surface (201a) of a flexible upper base layer (201), said layer having an upper surface to which the external force is applied; andthe second (204) films are resistance films and are formed on a surface (202a) of a lower base layer (202) opposed to said upper base layer (201).
ein Abstandsstück (5);
einen durchgehenden, ersten Widerstandsfilm (3, 203), der sich in einer ersten und zweiten Richtung erstreckt, wobei die erste und die zweite Richtung einander senkrecht kreuzen, und der genannte erste Widerstandsfilm (3, 203) eine äußere Verbindungselektrode (6, 7, 206, 207) an beiden Enden davon entlang der zweiten Richtung hat;
eine Mehrzahl zweiter Widerstandsfilme (4, 204), wobei die genannten zweiten Widerstandsfilme (4, 204) jeweils ein länglicher Streifen sind, die sich in eine die zweite Richtung kreuzende erstrecken und eine äußere Verbindungselektrode (10, 71, 11, 210, 211) an wenigstens einem Ende davon haben;
worin die genannte Bestimmungseinrichtung für eine niedergedrückte Position fähig ist, eine der genannten Koordinaten auf der Grundlage der Oberflächenwiderstandswerts des genannten ersten Widerstandsfilms zwischen einer der äußeren Verbindungselektroden des ersten Widerstandsfilms und der niedergedrückten Position zu bestimmen, dadurch gekennzeichnet, daß
ein Paar Grundisolierschichten (1, 201, 2, 201) einander gegenüberstehend mit einem gewissen Abstand dazwischen vorgesehen ist;
das genannte Abstandsstück zwischen den genannten Grundisolierschichten (1, 201, 2, 202) vorgesehen ist, um die Schichten beabstandet zu halten, aber zu gestatten, daß sich die Schichten (1, 201, 2, 202) einander nähern, wenn eine äußere Kraft auf eine der Schichten (1, 201, 2, 202) aufgebracht wird;
der genannte erste Widerstandsfilm auf einer inneren Oberfläche (1, 201a) einer der genannten Schichten (1, 201) vorgesehen ist; die genannte Mehrzahl von Widerstandsfilmen auf einer inneren Oberfläche (2a, 202a) der anderen der genannten Schichten (2, 202) vorgesehen ist; und
die genannte Bestimmungseinrichtung für die niedergedrückte Position des weiteren fähig ist, die andere der genannten Koordinaten auf der Grundlage des Ortes des zweiten Widerstandsfilm in der genannten Tafel zu bestimmen.
eine Gleichstromversorgungseinrichtung, um dem genannten ersten Widerstandsfilm (203) ein Gleichspannungspotential (V) durch eine der äußeren Verbindungselekroden (207) davon zuzuführen;
einen Schalter (312), der in einen ersten Zustand geschaltet wird, um allen äußeren Verbindungselektroden (211) der genannten zweiten Widerstandsfilme (204) ein Potential mit Massepegel zuzuführen, und in einen zweiten Zustand, um diese (211) von dem Potential mit Massepegel freizugeben; und
eine elektrische Potentialmeßeinrichtung (272) zum Messen der Potentiale aller der äußeren Verbindungselektroden (211) der genannten zweiten Widerstandsfilme (204) sowohl in dem ersten als auch in dem zweiten Zustand.
eine erste Potentialzuführeinrichtung, um dem genannten ersten Widerstandsfilm (3) ein Gleichspannungspotential (Vl) durch eine der äußeren Verbindungselektroden (6) des genannten ersten Widerstandsfilms (13) zu führen;
einen ersten Schalter (41), der elektrisch mit allen äußeren Verbindungselektroden (10) der genannten zweiten Widerstandsfilme (4) einzeln, abwechselnd für jeden zweiten genannten Widerstandsfilm verbunden ist;
einen zweiten Schalter (42) der synchron zu dem ersten Schalter (41) geschaltet wird und elektrisch mit der äußeren Verbindungselektrode (11) verbunden ist, die der äußeren Verbindungselektrode (10) gegenübersteht, die mit dem ersten Schalter (41) verbunden ist;
eine zweite Potentialzuführeinrichtung, um dem genannten zweiten Widerstandsfilm (4) ein Gleichspannungspotential (V2) durch den ersten Schalter (41) zuzuführen; und
eine elektrische Potentialmeßeinrichtung (43) zum Messen der Potentiale der zweiten Widerstandsfilme (4) durch den zweiten Schalter (42).
eine Gleichspannungspotentialzuführeinrichtung (81, 82) zum Zuführen eines Gleichspannungspotential einzeln zu dem genannten zweiten Widerstandsfilm (4);
eine Schaltereinrichtung (83), die mit einer wenigstens zweimal so großen Geschwindigkeit wie die Gleichspannungspotentialzuführeinrichtung (81, 82) schaltet, wobei die genannte Schaltereinrichtung (83) zum abwechselnden Zuführen eines Gleichspannungspotentials an die äußeren Verbindungselektroden (6, 7) des genannten ersten Widerstandsfilms (3) ist; und
eine elektrische Potentialmeßeinrichtung (84) zum Messen des Potential der äußeren Verbindungselektrode (6, 7) des genannten ersten Widerstandsfilms (3), wobei die Elektrode (6, 7) der Elektrode (6, 7) gegenübersteht, der das Gleichspannungspotential durch die Schaltereinrichtung (83) zugeführt wird.
eine erste Potentialzuführeinrichtung zum Zuführen eines Gleichspannungspotentials (V) durch eine der äußeren Verbindungselektroden (6) des genannten ersten Widerstandsfilms (3) zu dem genannten ersten Widerstandsfilm (3);
eine zweite Potentialzuführeinrichtung zum Zuführen eines Gleichspannungspotentials (V) zu der zweiten, äußeren Verbindungselektrode (71) der genannten zweiten Widerstandsfilme (4);
einen Schalter (72), der elektrisch mit den ersten, äußeren Verbindungselektroden (11) der genannten zweiten Widerstandsfilme (4) einzeln, abwechselnd für jeden zweiten genannten Widerstandsfilm (4) verbunden ist; und
eine elektrische Potentialmeßeinrichtung (43) zum Messen der Potentiale der ersten, äußeren Verbindungselektroden (11) der genannten zweiten Widerstandsfilme (4) durch den Schalter (72).
einen durchgehenden, ersten Widerstandsfilm (203), der sich zweidimensional erstreckt;
eine Mehrzahl länglicher, streifenförmiger, zweiter Filme (204); und
ein Abstandsstück (205), um den genannten ersten (203) und die zweiten (204) Filme beabstandet zu halten, wobei aber, wenn eine äußere Kraft auf den genannten ersten (203) Film ausgeübt wird, ermöglicht ist, daß sich der erste (203) und die zweiten (204) Filme einander an einer Position berühren, die der entspricht, wo die äußere Kraft angewendet wird;
dadurch gekennzeichnet, daß der erste Film (203) auf einer unteren Oberfläche (201a) einer flexiblen, oberen Grundschicht (201) gebildet ist, wobei die genannte Schicht eine obere Oberfläche hat, auf die die äußere Kraft angewendet wird; und
die zweiten (204) Filme Widerstandsfilme sind und auf einer Oberfläche (202a) einer unteren Grundschicht (202), der genannten oberen Grundschicht (201) gegenüberstehend gebildet sind.
un espaceur (5) ;
un premier film résistif continu (3, 203) s'étendant dans des première et seconde directions, les première et seconde directions se croisant perpendiculairement et ledit premier film résistif (2, 203) ayant une électrode de connexion externe (6, 7, 206, 207) sur ses deux extrémités le long de la second direction ;
une pluralité de seconds films résistifs (4, 204), lesdits seconds films résistifs (4, 204) étant chacun une bande longitudinale s'étendant dans une direction croisant la seconde direction et ayant une électrode de connexion externe (10, 71, 11, 210, 211) sur au moins une de ses extrémités ;
dans lequel ledit dispositif de détection de position poussée est adapté pour détecter une desdites coordonnées basée sur la valeur de résistance de surface dudit premier film résistif entre une des électrodes de connexion externes du premier film résistif et la position poussée, caractérisé en ce que
une paire de couches de base isolantes (1, 201, 2, 202) est prévue, opposées l'une à l'autre avec une certaine distance entre elles ;
ledit espaceur est disposé entre lesdites couches de base isolantes (1, 201, 2, 202) pour maintenir lesdites couches en éloignement mais pour permettre auxdites couches (1, 201, 2, 202) de s'approcher l'une de l'autre lorsque une force externe est appliquée à une des couches (1, 201, 2, 202) ;
ledit premier film résistif est prévu sur une surface interne (la, 201a) de l'une desdites couches (1, 201) ; ladite pluralité de films résistifs est prévue sur une surface interne (2a, 202a) de l'autre desdites couches (2, 202) ; et
le dispositif de détection de position poussée est en outre adapté pour détecter l'autre desdites coordonnées basée sur la position des seconds films résistifs dans ledit écran.
des moyens d'alimentation de potentiel de courant continu pour alimenter ledit premier film résistif (203) avec un potentiel de courant continu (V) à travers l'une des électrodes de connexion externe (207) de celui-ci,
un commutateur (212) commuté vers un premier état pour alimenter toutes les électrodes de connexion externes (211) desdits seconds films résistifs (204) avec un potentiel de niveau de masse, et vers un second état pour libérer celles-ci (211) du potentiel de niveau de masse ; et
des moyens de mesure de potentiel électrique (272) pour mesurer les potentiels de toutes les électrodes de connexion externes (211) desdits seconds films résistifs (204) à la fois dans les premier et second états.
des premiers moyens d'alimentation de potentiel pour alimenter audit premier film résistif (3) un potentiel en courant continu (Vl) à travers l'une des électrodes de connexion externes (6) dudit premier film résistif (3) ;
un premier commutateur (41) connecté électriquement avec toutes les électrodes de connexion externes (10) desdits seconds films résistifs (4) un par un, alternativement pour chacun desdits seconds films résistifs ;
un second commutateur (42) commuté en synchronisation avec le premier commutateur (41) et connecté électriquement à l'électrode de connexion externe (11) qui est opposée à l'électrode de connexion externe (10) connectée au premier commutateur (41) ;
des seconds moyens d'alimentation de potentiel pour alimenter les seconds films résistifs (4) avec un potentiel en courant continu (V2) à travers le premier commutateur (41) ; et
des moyens de mesure de potentiel électrique (43) pour mesurer les potentiels des seconds films résistifs (4) à travers le second commutateur (42).
des moyens d'alimentation de potentiel en courant continu (81, 82) pour alimenter un potentiel en courant continu auxdits seconds films résistifs (4) un par un ;
des moyens de commutation (83) commutant à une vitesse au moins deux fois supérieure à celle des moyens d'alimentation de potentiel en courant continu (81, 82), lesdits moyens de commutation (83) étant destinés à alimenter un potentiel en courant continu aux électrodes de connexion externes (6, 7) dudit premier film résistif (3) de manière alternative ; et
des moyens de mesure de potentiel électrique (84) pour mesurer le potentiel de l'électrode de connexion externe (6, 7) dudit premier film résistif (3), l'électrode (6, 7) étant opposée à l'électrode (6, 7) alimentée avec le potentiel en courant continu par les moyens de commutation (83).
des premiers moyens d'alimentation de potentiel pour alimenter ledit premier film résistif (3) avec un potentiel en courant continu (V) à travers une des électrodes externes (6) dudit premier film résistif (3) ;
des seconds moyens d'alimentation de potentiel pour alimenter un potentiel en courant continu (V) à la seconde électrode de connexion externe (71) desdits seconds films résistifs (4) ;
un commutateur (72) connecté électriquement avec les premières électrodes de connexion externes (11) desdits seconds films résistifs (4) un par un de manière alternative pour chacun desdits seconds films résistifs (4) ; et
des moyens de mesure de potentiel électrique (43) pour mesurer les potentiels des premières électrodes de connexion externes (11) des seconds films résistifs (4) à travers le commutateur (72).
un premier film résistif continu (203) s'étendant en deux dimensions ;
une pluralité de seconds films (204) similaire à des bandes longitudinales ; et
un espaceur (205) pour maintenir lesdits premiers et seconds films (203, 204) en éloignement mais, lorsqu'une force externe est appliquée sur ledit premier film (203), permettant audit premier film (203) et auxdits seconds films (204) de se contacter en une position correspondant à celle à laquelle la force externe est appliquée ;
caractérisé en ce que le premier film (203) est formé sur une surface inférieure (201a) d'une couche de base supérieure flexible (201), ladite couche ayant une surface supérieure à laquelle la force externe est appliquée ; etles seconds films (204) sont des films résistifs et sont formés sur une surface (202a) d'une couche de base inférieure (202) opposée à ladite couche de base supérieure (201).